Re: x264 benchmarks BFS vs CFS

[Jason Garrett-Glaser]

On Thu, Dec 17, 2009 at 3:00 AM, Kasper Sandberg <lkml@xxxxxxxxxxx> wrote:
> On Thu, 2009-12-17 at 11:53 +0100, Ingo Molnar wrote:
>> * Jason Garrett-Glaser <darkshikari@xxxxxxxxx> wrote:
>>
>> > On Thu, Dec 17, 2009 at 1:33 AM, Kasper Sandberg <lkml@xxxxxxxxxxx> wrote:
>> > > well well :) nothing quite speaks out like graphs..
>> > >
>> > > http://doom10.org/index.php?topic=78.0
>> > >
>> > >
>> > >
>> > > regards,
>> > > Kasper Sandberg
>> >
>> > Yeah, I sent this to Mike a bit ago.  Seems that .32 has basically tied
>> > it--and given the strict thread-ordering expectations of x264, you basically
>> > can't expect it to do any better, though I'm curious what's responsible for
>> > the gap in "veryslow", even with SCHED_BATCH enabled.
>> >
>> > The most odd case is that of "ultrafast", in which CFS immediately ties BFS
>> > when we enable SCHED_BATCH.  We're doing some further testing to see exactly
>
> Thats kinda besides the point.
>
> all these tunables and weirdness is _NEVER_ going to work for people.

Can't individually applications request SCHED_BATCH?  Our plan was to
have x264 simply detect if it was necessary (once we figure out what
encoding settings result in the large gap situation) and automatically
enable it for the current application.

Jason
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